Resolving dependencies... cabal: Could not resolve dependencies: [__0] next goal: ats-pkg (user goal) [__0] rejecting: ats-pkg-3.5.0.2, ats-pkg-3.5.0.1, ats-pkg-3.5.0.0, ats-pkg-3.4.0.8, ats-pkg-3.4.0.5, ats-pkg-3.4.0.4, ats-pkg-3.4.0.3, ats-pkg-3.4.0.1, ats-pkg-3.4.0.0, ats-pkg-3.3.0.7, ats-pkg-3.3.0.6, ats-pkg-3.3.0.5, ats-pkg-3.3.0.4, ats-pkg-3.3.0.1, ats-pkg-3.3.0.0, ats-pkg-3.2.6.4, ats-pkg-3.2.6.3, ats-pkg-3.2.6.2, ats-pkg-3.2.6.1, ats-pkg-3.2.6.0, ats-pkg-3.2.5.18, ats-pkg-3.2.5.17, ats-pkg-3.2.5.16, ats-pkg-3.2.5.13, ats-pkg-3.2.5.12, ats-pkg-3.2.5.11, ats-pkg-3.2.5.10, ats-pkg-3.2.5.6, ats-pkg-3.2.5.3, ats-pkg-3.2.4.6, ats-pkg-3.2.4.5, ats-pkg-3.2.4.4, ats-pkg-3.2.4.2, ats-pkg-3.2.4.0, ats-pkg-3.2.3.0, ats-pkg-3.2.2.3, ats-pkg-3.2.2.2, ats-pkg-3.2.2.0, ats-pkg-3.2.1.8, ats-pkg-3.2.1.2, ats-pkg-3.1.0.12, ats-pkg-3.1.0.6, ats-pkg-3.1.0.2, ats-pkg-3.0.0.11, ats-pkg-3.0.0.10, ats-pkg-3.0.0.4, ats-pkg-3.0.0.2, ats-pkg-3.0.0.1, ats-pkg-3.0.0.0, ats-pkg-2.11.0.10, ats-pkg-2.11.0.9, ats-pkg-2.11.0.8, ats-pkg-2.11.0.7, ats-pkg-2.11.0.1, ats-pkg-2.10.2.5, ats-pkg-2.10.2.2, ats-pkg-2.10.2.0, ats-pkg-2.10.1.8, ats-pkg-2.10.1.5, ats-pkg-2.10.0.20, ats-pkg-2.10.0.17, ats-pkg-2.10.0.11, ats-pkg-2.10.0.8, ats-pkg-2.10.0.2, ats-pkg-2.10.0.0, ats-pkg-2.9.0.2, ats-pkg-2.9.0.1, ats-pkg-2.9.0.0 (constraint from user target requires ==2.8.0.8) [__0] trying: ats-pkg-2.8.0.8 [__1] trying: http-client-tls-0.3.5.3 (dependency of ats-pkg) [__2] trying: tls-1.5.5 (dependency of http-client-tls) [__3] trying: x509-1.7.5 (dependency of tls) [__4] trying: async-2.2.3 (dependency of tls) [__5] trying: memory-0.16.0 (dependency of http-client-tls) [__6] trying: http-client-0.7.8 (dependency of ats-pkg) [__7] next goal: dhall (dependency of ats-pkg) [__7] rejecting: dhall-1.38.1 (conflict: ats-pkg => dhall>=1.11.0 && <=1.12.0) [__7] skipping: dhall-1.38.0, dhall-1.37.1, dhall-1.37.0, dhall-1.36.0, dhall-1.35.0, dhall-1.34.0, dhall-1.33.1, dhall-1.33.0, dhall-1.32.0, dhall-1.31.1, dhall-1.30.0, dhall-1.29.0, dhall-1.28.0, dhall-1.27.0, dhall-1.26.1, dhall-1.25.0, dhall-1.24.0, dhall-1.23.0, dhall-1.22.0, dhall-1.21.0, dhall-1.20.1, dhall-1.19.1, dhall-1.19.0, dhall-1.18.0, dhall-1.17.0, dhall-1.16.1, dhall-1.15.1, dhall-1.14.0, dhall-1.13.1, dhall-1.13.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=1.11.0 && <=1.12.0' from 'ats-pkg') [__7] rejecting: dhall-1.12.0 (conflict: http-client==0.7.8, dhall => http-client>=0.4.30 && <0.6) [__7] skipping: dhall-1.11.1, dhall-1.11.0, dhall-1.10.0, dhall-1.9.1, dhall-1.9.0, dhall-1.8.2, dhall-1.8.1, dhall-1.8.0, dhall-1.7.0, dhall-1.6.0, dhall-1.5.1, dhall-1.5.0, dhall-1.4.2, dhall-1.3.0, dhall-1.2.0, dhall-1.1.0, dhall-1.0.2, dhall-1.0.1 (has the same characteristics that caused the previous version to fail: excludes 'http-client' version 0.7.8) [__7] rejecting: dhall-1.31.0 (conflict: ats-pkg => dhall>=1.11.0 && <=1.12.0) [__7] skipping: dhall-1.26.0, dhall-1.20.0, dhall-1.16.0, dhall-1.15.0, dhall-1.4.1, dhall-1.4.0, dhall-1.0.0 (has the same characteristics that caused the previous version to fail: excluded by constraint '>=1.11.0 && <=1.12.0' from 'ats-pkg') [__7] fail (backjumping, conflict set: ats-pkg, dhall, http-client) After searching the rest of the dependency tree exhaustively, these were the goals I've had most trouble fulfilling: ats-pkg, dhall, base, tls, http-client, x509, http-client-tls, memory, async Try running with --minimize-conflict-set to improve the error message.